A variety of issues related to tangling of various hybrid transform
experiments.

Change-Id: I84dac65ff513f8b024407760df55fffa95e198de

This commit fixes unsafe simd / floating point interactions arising
from the current hybrid and 16x16 transform implementation.
These led to a raft of bugs and issues when the project was
built using VS2008 for Win32 though they did not show up with
the unix builds.

Gerrit makes a meal out of presenting the fix but all I have actually
done is indent the body of each function that uses floating point by
one level and bracket with emms instructions using  the function
vp8_clear_system_state(). See below.

function () {
  vp8_clear_system_state();
  {
  ... function body
  }
  vp8_clear_system_state();
}

This is almost certainly over the top in terms of number of emms
instructions but is a temporary measure pending implementation of
integer variants of each function to replace the floating point.

Limited testing suggests that this fixes the problems that arose for
Win32 VS2008 when the hybrid or 16x16 transforms were enabled.

Change-Id: I7c9a72bd79315246ed880578dec51e2b7c178442

Separates the entropy coding context models for 4x4, 8x8 and 16x16
ADST variants.

There is a small improvement for HD (hd/std-hd) by about 0.1-0.2%.
Results on derf/yt are about the same, probably because there is not
enough statistics.

Results may improve somewhat once the initial probability tables are
updated for the hybrid transforms which is coming soon.

Change-Id: Ic7c0c62dacc68ef551054fdb575be8b8507d32a8

With this change, even if hybridtransform8x8 experiment is off,
8x8 dct is used for the I8x8 mode. However note that the gains
observed with the hybridtransform8x8 experiment will now be less,
since part of the gain is now merged in.

Change-Id: I9afb3880906fd0a1368a374041fc08efcf060c54

for MBs using i8x8 prediciton mode when hybridtransform8x8 is not
enabled in configure.

Change-Id: I3e3c8bb1c0261108c1c71213ca9557b0ce558036

The non-void function didn't return a value in the default case.

Change-Id: Ie4c965315bedc189d2080dd65cf29d3347661946

Change-Id: I34569375e520759860504c3dfb17a2c27ceb9aed

The commit changed to use 3 rows above and 3 cols from left for SAD
scoring for selecting the best reference motion vector. The change
helped std-hd set by >.2% on psnr/ssim metrics.

Change-Id: Ifad3b528d0b4b6e3c22518af789d76eff23c1520

Removed spurious line that has no effect.

Change-Id: I9dc90babbbfcaca049d4a40dc996edc7de123e01

The high-precision (1/8) pel bit is turned off if the reference
MV is larger than a threshold. The motivation for this patch is
the intuition that if motion is likely large (as indicated by
the reference), there is likley to be more motion blur, and as
a result 1/8 pel precision would be wasteful both in rd sense
as well as computationally.

The feature is incorporated as part of the newmventropy experiment.
There is a modest RD improvement with the patch. Overall the
results with the newmventropy experiment with the threshold being
16 integer pels are:

derf: +0.279%
std-hd: +0.617%
hd: +1.299%
yt: +0.822%

With threshold 8 integer pels are:

derf: +0.295%
std-hd: +0.623%
hd: +1.365%
yt: +0.847%

Patch: rebased
Patch: rebase fixes

Change-Id: I4ed14600df3c457944e6541ed407cb6e91fe428b

Some cleanups on the transform size and type selection logic.

Change-Id: If2e9675459482242cf83b4f7de7634505e3f6dac

This reverts commit c5af82b7

There was a mismatch bug introduced by this patch. Hence reverting until it is fixed.

Some cleanups that will make it easier to maintain the code
and incorporate upcoming changes on  entropy coding for the
hybrid transforms.

Change-Id: I44bdba368f7b8bf203161d7a6d3b1fc2c9e21a8f

This commit merges those parts of the CONFIG_NEW_MVREF
that specifically relate to choosing a better set of candidate
MV references into the NEWBESTREFMV experiment.

CONFIG_NEW_MVREF will then be used for changes relating
to the explicit coding of a cost optimized MV reference in the
bitstream as part of MV coding.

Change-Id: Ied982c0ad72093eab29e38b8cd74d5c3d7458b10

Extend experiment to use both vectors from MBs
coded using compound prediction as candidates.

In final sort only consider best 4 candidates
for now but make sure 0,0 is always one of them.

Other minor changes to new MV reference code.
Pass in Mv list to vp8_find_best_ref_mvs().

Change-Id: Ib96220c33c6b80bd1d5e0fbe8b68121be7997095

Adds a new experiment with redesigned/refactored motion vector entropy
coding. The patch also takes a first step towards separating the
integer and fractional pel components of a MV. However the fractional
pel encoding still depends on the integer pel part and so they are
not fully independent. Further experiments are in progress to see
how much they can be decoupled without affecting performance.
All components including entropy coding/decoding, costing for MV
search, forward updates and backward updates to probability tables,
have been implemented.

Results so far:
derf: +0.19%
std-hd: +0.28%
yt: +0.80%
hd: +1.15%

Patch: Simplifies the fractional pel models:
derf: +0.284%
std-hd: +0.289%
yt: +0.849%
hd: +1.254%

Patch: Some changes in the models, rebased.
derf: +0.330%
std-hd: +0.306%
yt: +0.816%
hd: +1.225%

Change-Id: I646b3c48f3587f4cc909639b78c3798da6402678

Enable ADST/DCT of dimension 16x16 for I16X16 modes. This change provides
benefits mostly for hd sequences.

Set up the framework for selectable transform dimension.

Also allowing quantization parameter threshold to control the use
of hybrid transform (This is currently disabled by setting threshold
always above the quantization parameter. Adaptive thresholding can
be built upon this, which will further improve the coding performance.)

The coding performance gains (with respect to the codec that has all
other configuration settings turned on) are

derf:   0.013
yt:     0.086
hd:     0.198
std-hd: 0.501

Change-Id: Ibb4263a61fc74e0b3c345f54d73e8c73552bf926

Change-Id: I7524883fb29f42303fb46a5bc6772fbcf8781d1d

Change-Id: I323c429b453eec8c3b76c37f7e2a52da9dfe8d77

Change-Id: I3d585bae446c16fcf7a39d72c1bcd6468a7bb1a1

Useful to pass --target etc to this script on Jenkins.

Change-Id: I9b22339a211df543077bcc84bdef4460f3ca5c9c

The transform functions in experimental branch absorbed a scaling
factor of 4 to allow quantization steps closer to unit quantizer.
This commit added scaling code in between forward and inverse
transform to properly account for the scaling factor.

Change-Id: I9a573ddc1ffa74973b34800a5da1a56dbabe0949

Alternative strategy for finding a list of candidate motion
vectors to use as reference values in mv coding and as
nearest and near.

Sort by sad in vp8_find_best_ref_mvs() rather than just
pick the best. Allow 0,0 as a best ref option but not a
nearest or near unless there are no alternatives.

Encode/Decode verified on at least some clips.

Some commented out experimental and stats code still in place.

Gain over existing code averages about 1% on derf (alll metrics)
with improvement on all clips. Other test results pending.

The entropy coding of the mode (nearest/near etc) still
depends upon and requires the old "findnear" code so
this needs looking at and may provide room for further gains.

Change-Id: I871d7cba1d1c379c4bad9bcccce1fb19c46b8247

Change-Id: If4eb0fd60cc5bc2f32254e82e8d6cfa4120cb558

Change-Id: I8d1a2c664cbeb939cf23bcd414b23e19da760a14

Change-Id: Ifff660de60fb12d745092eafc17f6a49f6e1fb53

About 20% overall encoder speedup (vs. about 30% for sse4 version).

Change-Id: Ibf608a6a1bc94b14ec47e8046d3206b275b5a8bd

Change-Id: I887cdcf90b87736f2a3805420aa41eed93324bee